Disconnectable relay apparatus



Nov. 20, 1956 'J. STOECKLIN ET AL DISCONNECTABLE RELAY APPARATUS Filed July 18, 1955 BY/PM) JW 3912* TTORNEYS United States Patent DISCONNECTABLE RELAY APPARATUS Josef Stoecklin, Ennetbaden, and Mario Lura, Baden, Switzerland, assignors to Aktiengesellschaft Brown, Boveri & Cie, Baden, Switzerland, a joint-stock com- P y Application July 18, 1955, Serial No. 522,646

Claims priority, application Switzerland February 18, 1955 4 Claims. (Cl. 20050) This invention relates to relay apparatus and more particularly to relays such as overecurrent, differential, thermal and other types used for line protective systems and installed in central stations. These relays are manufactured for installation in protective casings which are permanently installed in place, the casings having, usually at the rear wall thereof, contact means which are complementary to contact means on the relay structure, and the arrangement being such that as the relay is inserted into its casing, the contact means on the relay engage the contact means in the casing. The contact means in the casing are permanently connected in the protective circuit and hence the relays may be automatically electrically connected into or removed from the protective circuit by inserting the same into or removing them from their casings, without the necessity of making any special connections by hand.

Various arrangements have been developed along this line to permit installation or removal of the relay structure per se relative to the protective circuit. Special precautions must be taken that the circuit of the apparatus is closed before the apparatus is lifted ofif the contacts.

Among the known forms of construction there are such apparatus, which together with the front plate, form an entity. By loosening the fixing screws, which connect the front plate of one relay with the relay case, the relay part, located at the two screws, may be removed. This form of construction has the drawback, that a considerable amount of frictional power must be overcome before extracting said relay part, because, at the same time, a considerable number of plugs must be removed at the risk that-when removing the plugs-the relay will be disconnected by jerks. By other forms of construction the switches are functioning at the front, which, after opening the cover, first must be reversed, making it necessary to remove a bolt at the place where the relay is going to be extracted and thereby causing unnecessary manipulation. Finally, there are forms of construction where the load, coming from the connecting terminals of the back of the relay is guided by means of a sliding device, fixed on an insulating plate, at the bottom of the box, the apparatus part being provided with corresponding tracks.

A drawer-like slider is inserted between these two rows of contacting tracks establishing connection between the upper track of the apparatus part and the guiding track of the bottom of the box. In this case the said slider must first be removed and then the actual part by means of two bolts may be disconnected, by means of which bolts it then may be seized and finally removed. The last mentioned form of construction requires a considerable amount of expense and therefore cannot be considered economical. The drawbacks of this known form of construction are eliminated through the invention further explained in the following: The invention concerns a telescopic device for electric apparatus, particularly relays, which, by guiding said relays, may be inserted in a case, the said relays being provided with 2,771,523 Patented Nov. 20, 1956- press-contacts or plug-contacts, connected with complementary contacts at the back of the case.

In accordance with the invention, the removable relay structure is provided with a lever, preferably in the form of a U-shaped member, having spiral open ended slots at the outer pivotally mounted ends of the legs of such member, the slots being adapted for a releasable connection with pins fixed at opposite sides of the casing in such manner that as the U-shaped member is turned about its pivot mounting, the relay structure is caused to be moved with great force longitudinally of itself further into or out of the casing, depending upon the direction of turning, thus causing the contacts at the back of the relay to engage or disengage respectively with or from the fixed contacts in the relay casing. A reversal of parts is likewise obvious, i. e. the pins can be fixed to the lever and the spiral slots provided on the casing. In either case, relative movement of the pin in the slot is reflected by movement of the relay frame either further into or out of the casing in which it has been initially inserted to the point where the contacts on the relay frame are close to the fixed contacts in the casing.

This arrangement has a considerable number of advantages. In the first place a very large amount of power for moving the relay is created by the leverage effected in turning the U-shaped member on its pivotal mounting and with which power the contacts on the relay and casing may be engaged or disengaged. Secondly, the position of the U-shaped member, near vertical or horizontal, tells the operator at a glance whether the relay is connected or disconnected in the protective circuit. Thirdly, the U-shaped member serves as a most convenient handle for carrying the relay to and from the casing.

According to a further aspect of the invention, releasable stop means may be provided for temporarily limiting the pivotal movement of the U-shaped member to the end that the pins on the casing will not unintentionally disengage entirely from the open end of the associated spiral slot as the U-shaped member is turned to a near horizontal position preliminary to removing the relay from the casing.

The invention is more particularly disclosed in a representative embodiment thereof about to be described, and by the accompanying drawings which illustrate such embodiment.

In the drawings,

Fig. l is a view in perspective showing the supporting structure or frame on which the relay mechanism (overcurrent, differential, thermal etc.) is mounted, and the casing in which the frame is adapted to slide to either connect or disconnect the relay. In order to simplify illustration, none of the details of the relay mechanism per se have been illustrated and most of the casing has been shown in phantom. However, the fixed, i. e. permanent contacts at the inside of the rear wall of the casing, and the complementary, coengaging contacts on the relay have been shown in full.

Fig. 2 is a detail of a modification showing releasable spring means which serve as a temporary stop for the U-shaped member in advance of withdrawal of the pins from the open end of the slots when disconnecting the relay so that the frame cannot unexpectedly be pulled entirely out of the casing.

With reference now to the drawings, the casing which is adapted to receive the relay is indicated mostly in phantom by the numeral 1. Such casing is adapted to be permanenly mounted on the wall in a station and includes two pairs of contacts 2 in the form of pronged sockets which are permanently connected in the protective system, the contact members 2 being mounted at the inside of the rear wall 1a of casing 1. The casing is open at the front for slidably receiving the relay per se which is mounted on a frame 3. The latter includes an upright member 4 at the rear thereof on which is mounted two pairs of contacts 5 in the form of contact plugs which are adapted to engage the fixed contacts 2 when the relay frame is pushed further into the casing, and be disengaged from those contacts when the relay frame is pulled in the opposite direction. To facilitate movement of the relay frame 3 in casing 1, the latter is provided with horizontally extending rails 6 at opposite sides thereof which are slidably arranged in channel members 7 which are secured to or made integral with the side walls 1b of easing 1.

As previously indicated, the principal object of the invention is to provide means for amplifying the power with which the relay is moved in the casing through the short distance required to engage'or disengage the contact members 2, which are fixed to the casing, with or from the contact members 5 which are fixed to the removable relay organization. For this purpose, it will be seen that the relay frame 3 includes forwardly projecting lugs 8 at each side at the front thereof which serve to pivotally mount, by means of pivot pins 9, the outer end portions of the legs 11 of a U-shaped member 11, such end portions being apertured at 12 to receive the pivot pins 9. Each of the legs includes an open ended slot 13 which partially surrounds the corresponding aperture 12 and pivot pin 9, and is arranged spirally with respect to the axis of pivot pin 9, i. e. the distance of the slot from the axis changes progressively in the nature of a cam. Pins 14 fixed in position and projecting inwardly from the side walls 1b of easing 1 engage in the slots 13 and hence it will now be evident that when the U-shaped member 11 is turned about the axis of pins 9, the entire relay frame 3 will be caused to be slidingly displaced horizontally in the casing. An upward rotative movement of the U-shaped member from a near horizontal position shown in Fig. 1 towards the vertical will cause the frame 3 to be displaced further inwardly of the casing 1 since the spiral slots 13 moving along the stationary pins 14 bring the latter closer to the axis of pivot pins 9.

As seen in Fig. 1, with the parts in the positions indicated, the movable plug contact members 5 on the relay frame occupy a position close to the fixed prong contact members 2 when pins 14 occupy those portions of the slots 13 near the one open end thereof which lie at the greatest distance from the axis of pivot pins 9. Consequently, when the U-shaped member 11 is moved upward by the operator causing the relay frame 3 to move further inward of easing 1, the contact members 2, 5 are caused to engage, and with considerable force attributable to the leverage afforded by the lever structure described. Conversely, the same amount of force is available for separating the plug contact members 5 on the relay from the prong contact members 2 on the casing when the U-shaped member is moved downward towards a horizontal position.

To limit rotative movement of the U-shaped member 11 about its support pivots towards the horizontal position it will be noted that a toe portion 15 is provided at the outer end of each leg 10 which is adapted to rise and stop against a cooperating abutting surface 16 at each side of the relay frame. Fig. 1 shows the U-shaped member with the toes 15 in abutment with the stop surfaces 16. In such position, the pins 14 are no longer engaged with the slots 13 and hence the relay frame 3 can then be withdrawn completely out of the casing 1.

Fig. 2 shows a modification which provides resilient means for stopping the U-shaped member 11 before the latter reaches the substantially horizontal position, and while the pins 14 are still engaged in the slots 13'. Such arrangement is desirable for preventing too sudden and unexpected withdrawal of the relay frame from the casing. In the particular construction illustrated in Fig. 2, such preliminary stop means is constituted by an arcuate shaped spring leaf 17 secured to the outer end of at least one leg 10 of the U-member 11, the spring leaf 17 being rotatable generally about the axis of pivot pin 9 and including a toe portion 18 arranged to come into abutment with the stop surface 16 in advance of the toe portion 15, and while the pins 14 are still engaged with the slots 13. In this position of the U-shaped member, the relay frame 3 thus cannot be withdrawn completely from the casing. To effect complete removal, the operator then presses downward upon the outer handle portion of the U-shaped member 11 thus bending the outer toe portion 18 of the spring leaf 17 downward against the restoring force of the spring until the pins 14 release from the slots 13 whereupon the whole relay frame 3 is then freed for complete withdrawal from the casing 1.

Several advantages inherent in the improved arrangement already have been explained. In addition to those advantages already enumerated, the invention, because of the development of power, for movement of the relay frame by the novel leverage, one is enabled to use coengaging contacts on the relay and casing respectively which require greater power to engage and disengage thus providing more certain electrical connections between the removable relay element and the protective system. Also, since the force of the rotating U-member when disconnecting the contacts, at the moment of disconnection, is directed downward, one avoids any unintentional falling out of the relay, and also eliminates undesirable jerk like motions of the relay. With the U-shaped member 11 in the horizontal position, one is also able to make on-the-spot tests of the relay by connecting testing wires to the terminals without completely withdrawing the relay frame from the casing.

In conclusion, it will be understood that the illustrated embodiment of the invention is to be considered typical rather than limitative of the structural organizations possible within the scope of the invention as defined in the appended claims. Moreover, while plug and prong-socket type contacts have been illustrated, it wil be obvious that press type coengaging contacts may be utilized.

We claim:

1. Diseonnectable relay apparatus comprising a casing having a front opening, fixed contact means disposed on the inside of the rear wall of said casing, a relay frame adapted to be slidably inserted in said casing through said front opening, said relay frame including relay contact means at the rear thereof for connection with and disconnection from said fixed contact means, a U-shaped lever, the outer ends of the leg portions of said lever being pivotally mounted on the front portion of said frame on co-axially arranged pivot means for rotation about a horizontal axis and means responsive to pivotal movement of.

' said lever for forcibly moving said relay frame and hence saidrelay contact means towards or away from said fixed contact means to connect or disconnect said contact means, respectively, depending upon the direction of movement of said lever, last said means including horizontal co-axially placed pins at opposite sides of said casing, and open-ended like spiral slots at the outer leg portions of said lever arranged spirally about the axis of rotation of said lever for cooperation with said pins, the open ends of said spiral slots being further away from the axis of rotation of said lever than the opposite closed ends thereof, said pins being engaged in said slots through the open ends thereof upon a horizontal insertion of said relay frame into said casing with said lever in a substantiallyhorizontal position and subsequent rotation of said lever into a vertical position serving to move said spiral slots along said pins thereby to effect a pulling movement of said lever and relay frame and the contact means at the rear thereof inwardly of said casing for connection with said fixed contact means at the inner side of the vertical rear wall of said casing, rotation of said lever from the vertical position toward the horizontal position serving to move said slots in the opposite direction along said pins thereby pushing said relay frame and retracting said contact means thereon from said fixed contact means.

2. Relay apparatus as defined in claim 1 and wherein said lever is provided with a stop limiting movement thereof towards the horizontal direction.

3. Relay apparatus as defined in claim 2 wherein said stop is constituted by a toe portion on said lever engageable with a fixed abutment on said relay frame.

4. Relay apparatus as defined in claim 1 and which further includes resilient means carried by said lever and engageable with a portion of said relay frame to provide an intermediate stop for said lever prior to release of said pin from the open end of said slot upon rotation of said 15 lever towards the horizontal position when disconnecting said relay contact means from said fixed contact means.

References Cited in the file of this patent UNITED STATES PATENTS 1,073,281 Palmer Sept. 16, 1913 1,511,408 Kries Oct. 14, 1924 1,729,864 Brown Oct. 1, 1929 2,409,289 Levin et al. Oct. 15, 1946 10 2,510,944 Auerbach June 13, 1950 FOREIGN PATENTS 139,444 Australia Oct. 16, 1947 156,632 Great Britain May 8, 1922 424,525 Italy Aug. 22, 1947 

